Xapian discuss - Dec 2008 - Newbie Question: Indexing and searching multiple fields

I've recently heard of Xapian and was taking a look at it in my spare
time. I have some experience with Ferret, a Ruby IR library, and I
have some questions about Xapian.

Ferret's indexes are similar to Lucene's, and support multiple fields
per document. Now, from reading Xapian's documentation, I know it can
do something similar through values. However, I wasn't able to find
clear instructions for how to search by these values.

For example, let's say I'm indexing documents with authors, titles and
potentially long bodies. In Ferret, each one would be a separate
field, and if I wanted to find all documents written by author "A", I
could pass it an "author:A" query, and it would return those to me.

Now, I know this is possible in Xapian, because I've googled up a few
messages that alude to it, but I haven't found clear instructions on
how to do it. I imagine title and author would be saved as values in a
Xapian docuent, and the body would be the document's data. But how
should I set up the index and Enquires so that it's possible to use
queries like "author:A"?

If this is documented somewhere, I probably missed it. I would
appreciate a pointed to the right documentation :).

-- 
Bira
http://compexplicita.wordpress.com
http://compexplicita.tumblr.com

Bira wrote:
> Ferret's indexes are similar to Lucene's, 
Actually Ferret's indexes were Lucene's - Ferret is Lucene ported to 
Ruby. Then it seems the Ferret author rewrote things and used a 
different file format...
http://rubyforge.org/forum/forum.php?forum_id=9058

Charlie

On Thu, Dec 4, 2008 at 11:30 AM, Charlie Hull <charlie at juggler.net>
wrote:
> Bira wrote:
>
>> Ferret's indexes are similar to Lucene's,
>
> Actually Ferret's indexes were Lucene's - Ferret is Lucene ported
to
> Ruby. Then it seems the Ferret author rewrote things and used a
> different file format...
> http://rubyforge.org/forum/forum.php?forum_id=9058
 I'm aware of that :). I just mentioned that in passing because of
 their ability to contain multiple fields for each document (I think
 Lucene does that too). Xapian seems to handle this a little
 differently, with values, which gave rise to my question.

 --
 Bira
 http://compexplicita.wordpress.com
 http://compexplicita.tumblr.com

Quoting Bira <u.alberton at gmail.com>:
> If this is documented somewhere, I probably missed it. I would
> appreciate a pointed to the right documentation :).
I asked similar questions and got some good answers:
http://lists.xapian.org/pipermail/xapian-discuss/2008-November/006067.html

Also, don't gloss over the Glossary :), it's full of preciousss  
nuggets which tend to put things into context:
http://www.xapian.org/docs/glossary.html

Cheers
Henry